Projection welding is in group of resistance welding. In this welding process where
weld joint is produced by heating is obtained from electrical resistance flow through
the work, which held under electrode pressure. The localized welding joint is made
by this welding method.
Projection welding principle:
The working principle of projection welding is more or less similar of spot welding.
The two surfaces of weld metal are held together in under pressure by the electrodes.
When an electrical current flown through the weld electrode, it causes the projecting
metals are melts and fuse the both material which is contacted. Thus the weld joint
In single operation a number of joint is made. The joint strength is depend on nature
of projection. There are three types of projections are used in projection welding
The cone type
The button type
The spherical type
The button type projection is used for joining of thin flat sheet metals (24-13 gauge).
The cone type projection is used on 12 to 5 gauge metal sheets. The spherical type
projection is used on higher thickness of metal.
Principle diagram of projection welding
Advantages of Projection welding:
A many number of weld joint can be performed at a time.
Rust, coating, oil etc. are not affected in this welding process.